GATE 2022 : Electrical Measurement Quiz 7

Which of the following method is not applicable for reduction of phase angle error in current transformer?

Consider a current transformer (CT), its primary winding carries 200 A, and secondary measured 0.495 A. Percentage ratio error (%) is ________. [Take 400/1 A, 10 VA, 0.8 p.f. CT for analysis].

A Lissajou pattern observed on an oscilloscope is stationary and has 5 horizontal tangencies and 2 vertical tangencies. It the frequency of horizontal input is 1,000 Hz, then frequency of vertical input is?

A current transformer has a bar primary and 250 secondary turns. The requisite flux set in the core by 75 AT in the primary winding. The secondary supplies a current of 4 A to a non-inductive burden of 1 Ω resistance. Neglecting the effects of magnetic leakage and iron, copper losses, the actual ratio is

The x–deflection plates of a CRT are 20 mm long and 5mm apart. The centre of the plate is 25cm away from the screen. The accelerating voltage is 3000V. What is the deflection sensitivity?

A current transformer has a bas primary & 200 secondary turns ratio. The secondary winding burden is an ammeter of impedance (1.2+j0.5) Ω. The secondary winding has an impedance of (0.2+j0.3) Ω. The core required a current of 100 A for magnetizing & 50 A for core loss. How many turns could be reduced in the secondary winding in order that the ratio error be zero for this condition? The ammeter in the secondary winding circuit indicates 5 A.